The present invention relates to an improved flowline switching apparatus and particularly to an improved flowline switching apparatus for directing through flow line (TFL) tools to one of a plurality of well strings from a single source. Such switching apparatus is used primarily underwater for connections to underwater oil and gas wells and is remotely controlled.
The G. E. Lewis et al U.S. Pat. No. 3,674,123 illustrates a prior flowline switching apparatus having a frusto-conical rotor in a frusto-conical housing with a tubular passage through the rotor communicating from a single upper port to selected ones of a plurality of lower ports. The base of the rotor has a single recess which is adapted to be engaged by one of a plurality of actuator plungers to lock it in a preselected position and a reed switch is associated with each plunger to indicate the locked positioning of the plunger in the recess.
The P. S. Putnam U.S. Pat. No. 3,877,520 discloses a conical housing and a tube connecting from the top central port to a lower rotary plate. The plate is rotated by a hydraulic motor to position the lower end of the tube in alignment with one of two ports. A fluid actuated stab-in connector is positioned at the lower end of the tube to make a positive connection to the lower port.
The P. S. Sizer U.S. Pat. No. 3,542,125 discloses a rotary selector for submerged wellheads. Rotation is accomplished with power cylinders having ratchet connections to teeth on a ratchet wheel and a pinion drive is used to provide an indication of the position of the pivoting arm.
Other patents of interest include the J. T. Dean U.S. Pat. No. 3,396,789 which discloses a rotary TFL tool holder with microswitches to indicate the holder position and the B. H. Van Bilderauk U.S. Pat. No. 4,133,418 which discloses a flowline selector with a rotatable plate rotating a tube to provide different connections, the rotations being produced by vertical movement of a piston converted to rotation by the interaction of a cam and cam follower.
Such devices are generally used in subsea locations where remote rotation, locking and position indication are generally required by the operator of the well.
None of the prior art suggests the improved features of the present invention for balancing, locking, sealing and indicating.
There is no teaching of the use of a single position locking device nor of a single indicating device to provide indication of one of multiple positions.